PVD coatings have the advantages of high hardness, low friction coefficient, good wear resistance and great chemical stability. At first, the successful application of PVD coatings in high-speed steel cutting tools attracted the attention of the manufacturing industries of various countries in the world. While researching and developing high-performance, high-reliability coating equipment, researchers also carried out deeper application development in cemented carbide and ceramic tools. Compared with the CVD process, the PVD process need lower processing temperature, it has no effect on the bending strength of the tool material when the temperature is lower than 600°C. The internal stress state of the PVD coating is compressive stress so it is more suitable for the hard alloy sophisticated tools. Besides, PVD process has no negative influence on the environment and it is in line with the development direction of modern green manufacturing. Nowadays, PVD coating technology is widely applied to the coating treatment of cemented carbide end mills, drills, step drills, oil hole drills, reamers, taps, indexable milling inserts, turning insert, special tools, welding tools, etc.

PVD technology improves the bond strength between the thin film and the tool substrate, and also the coating composition was developed into TiC, TiCN, ZrN, CrN, MoS2, TiAlN, TiAlCN, TiN-AlN, CNx, DLC, and ta- C and other multiple composite coatings from the first generation of TiN.